Laptop SODIMM Swap - Testing Laptop Memory One Module At A Time

This set of photos of swapping SODIMM's is a web based illustration for The Laptop Repair Workbook. In many troubleshooting scenarios, it laptop memory will be tagged as a possible culprit. The only way to eliminate memory as a potential problem is to swap it out and see if the problem is fixed. Most laptop users don't have access to a pile of spare parts to play the swapping game, but in the case of memory, the spare may already be available in the laptop for you. This particular Dell running Windows 2000 was equipped with 512 MB of RAM. One screw removes the access panel so we can see what we have.

Sure enough, the laptop memory is split between two SODIMM's, 256 MB each. As the modules are facing each other in this design, you see a different side of each module in the picture to the right. Many designs have the two SODIMM's stacked over each other in a deeper bay, though the connectors are usually staggered a little so they aren't exactly in line. Many older laptops had some or all of the system memory soldered to the motherboard, which is a real drag if you're troubleshooting, or if a memory chip has indeed failed. Unless you have advanced soldering skills and decent equipment, replacing a surface mounted RAM DIMM is just not a likely repair.

aptop memory modules are held in place a little spring clip on either end. You can pretty much always spring them back so the SODIMM pops up on its own with just your fingernails for tools.Note the angle of the module to the left. That's it's unsprung, or relaxed position. You have to angle it about the same when you go to install it. If I kept raising the SODIMM until it flipped over the connector and sat on the other side, it would look just like the second module, with the label down. the two connectors are mirrored.


Top the left I'm pulling out the second memory module, you can see the two sided connector that it sits in pretty clearly. When you have two memory modules in a laptop, it may work with either memory slot filled, or one the design may require that one slot is always filled first. In this Dell, even though the slots are labeled "A" and "B", it turns out the laptop will run with either one filled. So it's a trivial matter to put one module aside and install the other. If you don't have multiple SODIMMs installed and don't know where to buy one, try the memory advisor at Crucial.

I've put aside the first SODIMM removed and I'm installing the second one from Slot A into Slot B. It turns out the laptop worked fine. So I took it out and put the other SODIMM in Slot A. Laptop still worked fine. So the problem with the video in this case had nothing to do with the memory. If I'd been troubleshooting a blue screen of death (BSOD) failure on overheating, I'd have run the laptop for a while with just one module, and if it didn't have problems, I'd have tried it for a while with the other.

The last thing you want to see when you open up your laptop to try a memory swap is permanently installed RAM. That's the deal with this older Toshiba to the left, the 256 MB of factory installed RAM is in the form of DIP chips soldered to the motherboard. There is a SODIMM memory slot in the foreground which allows you to upgrade the memory capacity, but it's usually not possible to bypass failed RAM on the motherboard. In other words, if one of those chips fails, adding a SODIMM to the system won't help unless there's some way to inform the BIOS to ignore the soldered RAM. I didn't find a jumper!